1. Field of the Invention
The present invention relates to a method for forming a high-resolution pattern, and more particularly to a method for forming a high-resolution pattern having a high aspect ratio, comprising the steps of: an attachment step of attaching a dry film resist onto a substrate; an exposure step of exposing a dry film resist to light either by irradiating a focusable energy beam directly onto the dry film resist without using a mask or a diffractive optical element, or by projecting a specific wavelength range of light onto the dry film resist through a mask or a diffractive optical element, to pattern the dry film resist into the desired shape, thus forming a pattern; a pattern template-forming step of removing the exposed region using a development process; and a deposition step of depositing a functional material into the region from which the dry film resist was removed.
2. Description of the Prior Art
Generally, photolithography is used to form patterns for use in electronic devices. As used herein, the term “photolithography” refers to a technique of forming a shape using solubility resulting from a photochemical reaction. Specifically, photolithography comprises inducing a photochemical reaction on either a film sensitive to a given wavelength of light or a liquid photoresist, selectively depending on a portion exposed to light passed through a mask and a portion unexposed to the light, and subjecting the resulting film or photoresist to various processes, including development, deposition and removal, to finally make the desired pattern.
However, this photolithography method has problems in that a large amount of material is wasted and a process is complicated, leading to a reduction in efficiency. Also, because a large-area mask is used, it is difficult to implement a new design in a short time.
Also, in a thick film process of depositing a functional material for patterns to a thickness of the micrometer scale or larger using a process such as sputtering or CVD in a short time, photolithography is unsuitable in terms of process efficiency. Thus, to overcome these problems with photolithography, an inkjet patterning method that can be used to make patterns directly on a substrate without using any mask has been proposed.
This inkjet patterning method will now be described with reference to FIGS. 1a and 1b. 
As shown in FIG. 1a, a functional material of forming a pattern is deposited on a substrate 10 from an inkjet print head H, and is dried to remove an unnecessary ink carrier vehicle from the functional material. To aid in the understanding of the prior inkjet patterning method, the following example is given. The content of a functional material to be patterned, having a specific gravity of 10, is assumed to be 50 wt % based on the total weight of ink. Also, the content of a carrier vehicle(s) having an average specific gravity of 1, to be removed upon drying, is assumed to be 50% based on the total weight of the ink. Herein, the volume fraction of the fractional material based on the total volume of ink is about 9%.
Omitting complex physical phenomena to promote understanding, it is assumed that the linewidth that can be patterned with an inkjet is fixed, and that a uniform decrease in thickness occurs. As a result, the thickness of a pattern remaining after drying is only 96 of the thickness of an initial pattern. When such an inkjet is used to form a pattern, there is a problem in that an undesired excessive decrease in thickness occurs depending on the composition of ink, and this phenomenon is shown in FIG. 1a. Also, to form the pattern so that it has high resolution, that is, to reduce width, it is general to reduce the size of an ink drop. When a smaller ink drop is used in order to achieve high resolution as described above, a smaller amount of ink is deposited per unit area, as shown in FIG. 1b. As a result, the thickness of the resulting pattern is decreased in proportion to the decrease in linewidth, and thus it is physically difficult to achieve both objects of reducing linewidth alone and simultaneously maintaining the desired pattern thickness.
Also, when the size of the ink drop (i.e., functional material) is reduced to achieve high resolution, the targeting error of the ink drop increases relative to the scale of the pattern, thus causing a serious patterning error and forming an incorrect pattern.